Charging systems for batteries in electric vehicles, in one known form, provide a constant charge level when the electric vehicle is connected to the charging system. The charging system begins to charge the battery and then ceases charging once the battery is fully charged. The battery charging rate changes depending on the level of charge currently stored in the battery. An empty battery charges at a faster rate than one that is fuller. These known charging systems, however, do not account for the current charge level remaining on the battery, the thermal state of the battery, or external factors such as when the electric vehicle may be used again. Applying constant charge can be both cost and energy inefficient and detrimental to the durability and longevity of the battery.
In addition, a battery operates more efficiently and effectively at a temperature of approximately 75° Fahrenheit. If the temperature of the battery, due to ambient temperature or other factors, is very cold, then the battery outputs less power. On the other hand, high battery temperature reduces the lifetime of the battery. Also, by charging immediately upon being plugged in, the battery is unable to take advantage of a less expensive electrical utility rate available, for instance, late at night or very early in the morning.
Currently, when a driver resumes use of a vehicle after an extended time, the vehicle passenger compartment, also known as the cabin, will have a temperature equalized with its surroundings. As a result, when resuming vehicle use, the passenger compartment will be undesirably hot or cold if the ambient temperature is likewise hot or cold. Accordingly, further improvement in the art is desirable.